Effectiveness of Mediterranean Diet vs. DASH Diet in Reducing Cardiovascular Risk Factors

1
Effectiveness of Mediterranean Diet vs. DASH Diet
in Reducing Cardiovascular Risk Factors

• Hannah Lapkin
• GNUR 450

2
Background

• More than 2, 200 Americans die daily from CVD
• One death every 39 seconds
• Cause of 1/6 deaths in U.S. in 2007
• Major risk factors
• Hypertension (gt120/80 mmHg) 33.5
• High Cholesterol (gt240 mg/dl) 15
• Obesity (BMI gt 30 kg/m2) 33.7
• Financial Implications
• Estimated cost of CVD 268 billion
• Cardiovascular operations/procedures increased
  27 from 1997

3
PICOT Question

• In patients with the cardiovascular disease risk
  factors of hypertension and elevated cholesterol,
  how does the Mediterranean diet compare with the
  DASH diet in effectively reducing blood pressure
  and serum cholesterol levels over six months with
  bi-monthly counseling with an RD?
• P High-risk CVD patients
• I Mediterranean diet
• C DASH diet
• O Reduced blood pressure and cholesterol
• T 6 months
• Significance

4
Literature Review

• DASH Diet
• High consumption of fruits, vegetables, whole
  grains, nuts/legumes, low-fat dairy products
• Low consumption of sodium, red/processed meats,
  saturated/total fat
• Used in U.S. for prehypertensive/hypertensive
  individuals
• Studies show significant reductions in total/LDL
  cholesterol and estimated CHD risk
• Mediterranean Diet
• Composed of
• Abundance of plant foods
• Minimal red and processed foods
• Moderate amount of dairy products
• Olive oil as main lipid source
• Low-moderate consumption of wine with meals
• Evidence demonstrates
• Lower serum triglycerides, cholesterol, and
  systolic/diastolic blood pressure

5
Table of Relevant Studies
Study Results Gaps
Kastroini, Milionis, Esposito, Guigliano, Goudevenos, Panagiotakos. 2011 -Adherence to Med. Diet reduced waist circumference, triglycerides, hypertension, glucose, and increased HDL -No specified details of Med. Diet -Inability to control for confounders
Levitan, Wolk, Mittleman. 2009. -Greater consistency with DASH associated with lower heart failure events and reduced blood pressure and LDL/HDL cholesterol -Only looked at men ages 45-79 -DASH diet component score was not validated
Serra-Majem, Roman, Estruch. 2006 -Med. Diet associated with improved lipoprotein levels, metabolic syndrome, and myocardial and CVD mortality in obese patients with previous MI -Identified that no previous RCT had determined the extent to which the Med. diet is more effective than typically low-fat CVD diet (DASH)
Sofi, Abbate, Gensini, Casini. 2010 -Adherence to Med. diet has significant protective factors on overall mortality and cardiovascular incidence and mortality -Studies of short duration -Limited ability to transfer adherence score to the general population
Swain, McCarron, Hamilton, Sacks, Appel. 2008. -All diets improved cardiovascular risk factors but the blood pressure, cholesterol, and overall risk was lowered the most in higher protein diets. -Only a 19-week study -Didnt investigate adherence of each diet in free-living individuals
Tyrovolas Panagiotakos. 2010 -Fish consumption lowers CVD risk with decreased HTN, high cholesterol, and all-cause mortality. -Daily fruit/vegetable consumption reduces risk of MI -Identified that studies need to determine the feasibility of the integration of the Mediterranean diet into other countries and cultures.
6
Search Strategy

• Databases
• EbscoHost
• Ovid
• Pub Med
• Search Terms
• Cardiovascular disease
• Heart disease
• DASH diet
• Mediterranean
• Cholesterol
• Hypertension

• Study inclusion Criteria
• English-language
• Years 2007-2012

7
Design
DASH Diet Mediterranean Diet
Energy Level 2100 kcal 2100 kcal
Total Fat 27 37
Saturated Fat 6 6
Carbohydrates 55 45
Protein 18 18
Cholesterol 150 mg 150 mg
Fiber 30 g 30 g
Recommendations 6-8x whole grains, 4-5x fruit, 4-5x vegetables, 2-3x low-fat/fat-free dairy, 2-3x fats/oils, sweets/added sugar (5x weekly), nuts/seeds/legumes 4-5x weekly) 1-2x fruit, 2 vegetables, 1-2x olive oil, bread, pasta, rice, couscous (preferably whole grain) at every meal 2x low-fat dairy with herbs and spices (instead of salt) daily 2x white meat, 2 seafood, 2-4x eggs, 2 legumes, 3 potatoes, less than 2x red/processed meats, less than 2x sweets weekly, wine in moderation

• Pretest-Posttest experimental design
• Randomized into two diet arms
• Each of 50 individuals
• Stratified equally into men and women
• 6 months
• Bi-monthly counseling with a trained RD
• Evaluation
• BP readings at baseline, monthly, and at end
• Serum cholesterol values assessed at baseline,
  3-month mark, and end
• Food frequency questionnaires bi-monthly
• Adherence test

8
Sample

• Method
• Research nurses will recommend study to patients
  at a cardiac unit that meet inclusion/exclusion
  criteria
• Stratified random sampling by gender
• Size
• 50 men/50 women
• 50/each diet arm
• Inclusion/Exclusion

Inclusion Criteria Exclusion Criteria
Blood pressure gt120/80 mmHg gt160/100 mmHg
Cholesterol gt220 mg/dL gt280mmHg
Diet Must accept and enjoy diet plans from BOTH arms Food allergies
Age gt 35 years lt 35 years
Medication NOT on blood pressure or cholesterol medication ON blood pressure or cholesterol medications
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Methods for Data Collection

• Blood pressure readings
• Baseline
• Monthly
• Serum cholesterol blood draws
• Baseline
• Month 3
• End of Month 6
• 2008 NHANES Food Frequency Questionnaires
• 110-food item list
• Bi-monthly with counseling sessions
• Ensure adherence
• Food Diaries
• To review with RD and ensure accurate FFQ
  responses

10
Intervention Protocol

• Two RDs working in a cardiology unit will deliver
  intervention through bi-monthly counseling
• Assigned to either DASH/Mediterranean Diet arm
• Must be similar in personality
• Will take personality test to ensure similarity
• Training program to ensure fidelity
• Trained on specifics of each diet, nutrient
  composition and energy requirements, optimal
  methods to implement the goals
• Ensure RDs are equally knowledgeable on their
  assigned diet arm and can adequately counsel
  participants.

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Procedures for Data Collection

• Bi-monthly counseling sessions
• Review and analyze food diaries
• Offer suggestions on improving adherence to
  assigned diet
• Provide assistance on following assigned diet
• RD will chart on each counseling session using
  de-identified data (identification numbers for
  participants)
• Food Frequency Questionnaires completed by
  participants at time of counseling session
• Trained laboratory technician will
• Take blood pressure readings monthly
• Do blood draws at baseline, 3-month mark, end to
  assess cholesterol values
• Research analysts will assess
• RD chart notes
• Food Frequency Questionnaires
• Blood pressure readings
• Serum cholesterol values

12
Measures for Data Collection

• Blood pressure readings and blood tests
• Reliability extremely reliable
• Laboratory technicians will also be
  highly-trained to enhance reliability
• Validity extremely valid
• Highly-trained lab technicians also enhances
  validity
• Food Frequency Questionnaires
• Reliability Moderately reliable
• Hindered due to self-reporting may report what
  they think researchers want to see
• Validity Deemed valid sources of adherence in a
  number of nutritional experiments

13
Proposed Data Analysis Plan

• Independent t-test
• Comparing different diet arms in two groups
• Repeated measures analysis of variance (ANOVA)
• Study participants will be assessed at 3
  different points of time

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Human Subjects Issues

• Approved by Loyola IRB
• Informed of study through research nurse
• De-identified data to minimize potential biases
• Identification numbers received at time of
  consent
• Participants will consent to participation
  through signed waiver
• Informed consent waiver
• Statement of participant status
• Study goals
• Type of data collected and procedures used
• Nature of commitment
• Sponsorship of study
• Method of participant selection
• Potential risks and benefits
• Alternative treatments
• No diet therapy was unethical

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Study Challenges

• Financially difficult
• Bi-monthly counseling for 100 participants
• Time commitments
• Bi-monthly counseling appointments
• Food logging
• Small sample size
• Maybe too small for statistical power
• Potential limited diversity
• Consequently limiting generalizability
• Selection bias due to convenience sampling
• Threat to validity
• Self-reporting inaccuracies of food frequency
  questionnaires
• Only provide broad, general view of adherence

16
References

• Fundacion Dieta Mediterranea. (2011). The FDM
  presents the new Mediterranean diet pyramid.
  Retrieved from http//fdmed.org/en/the-fdm-present
  s-the-new-mediterranean-diet-pyramid/
• Kastroini, C., Milionis, H., Esposito, K.,
  Guigliano, D., Goudevenos, J., Panagiotakos, D.
  (2011). The effect of Mediterranean diet on
  metabolic syndrome and its components A
  meta-analysis of 50 studies and 534,906
  individuals. Journal of the American College of
  Cardiology, 57(11), 1299-1313.
• Levitan, E., Wolk, A., Mittleman, M. (2009).
  Relation of consistency with the dietary
  approaches to stop hypertension diet and
  incidence of heart failure in men aged 45 to 79
  years. American Journal of Cardiology, 104, pp.
  1416-1420.
• Roger, V., Go, A., Lloyd-Jones, D., Adams, R.,
  Berry, J., Brown, T., Carnethon, M., Dai, S., de
  Simone, G., Ford, E., Fox, C., Fullerton, H.,
  Gillespie, C., Greenlund, K., Hailpern, S., Heit,
  J., Ho, P., Howard, V., Kissela, B., Kittner, S.,
  Lacklund, D., Lichtman, J., Lisabeth, L., Makuc,
  D., Marcus, G., Marelli, A., Matchar, D.,
  McDermott, M., Meigs, J., Moy, C., Mozaffarian,
  D., Mussolino, M., Nichol, G., Paynter, N.,
  Rosamond, W., Sorlie, P., Stafford, R., Turan,
  T., Turner, M., Wong, N., Wylie-Rosett, J.
  (2010). Heart disease and stroke statistics2011
  update A report from the american heart
  association. Circulation, 123, pp. e18-e209.
• San Vincente, R., Perez, I., Ibarra, J.,
  Berranondo, I., Uribe, F., Urraca, J., Samper,
  R., Aizpurua, I., Almagro, F., Andres, J.,
  Ugarte, R. (2008). Clinical practice guideline on
  the management of lipids as a cardiovascular risk
  factor. Retrieved from http//www.guideline.gov/co
  ntent.aspx?id15711searchbasquemediterraneandi
  et
• Serra-Majem, L., Roman, B., Estruch, R. (2006).
  Scientific evidence of interventions using the
  Mediterranean diet A systematic review.
  Nutrition Reviews, 64 (2), p. S27-S47.
• Sofi, F., Abbate, R., Gensini, G., Casini, A.
  (2010). Accruing evidence on benefits of
  adherence to the Mediterranean diet on health An
  updated systematic review and meta-analysis.
  American Journal of Clinical Nutrition, 92, pp.
  1189-1196.
• Swain, J., McCarron, P., Hamilton, E., Sacks, F.,
  Appel, L. (2008). Characteristics of the diet
  patterns tested in the optimal macronutrient
  intake trial to prevent heart disease
  (omniheart) Options for a heart-health diet.
  Journal of the American Dietetic Association,
  108, pp. 257-265.
• Tyrovolas, S. Panagiotakos, D. (2010). The role
  of Mediterranean type of diet on the development
  of cancer and cardiovascular disease in the
  elderly A systematic review. Maturitas, 65, pp.
  122-130.
• U.S. Department of Health and Human Services
  (2006). Your guide to lowering your blood
  pressure with DASH Dash eating plan. NIH
  Publication No. 06-4082.